import React, { Component } from 'react'

export default class Demo extends Component {
  state = { count: 0}

  add = () => {
    // 对象式的setState
    /* const value = this.state.count * 1;
    console.log(value)
    this.setState({count: 1}, () => {
      console.log(this.state.count)
    });

    console.log("12行的输出", this.state.count);  // 0 */

    // 函数式的setState
    /* this.setState((state, props) => {
      console.log(state, props);
      return {count: state.count + 1}
    }) */

    this.setState( state => ({count: state.count + 1}) )
  }
  render() {
    return (
      <div>
        <h1>当前求和为：{this.state.count}</h1>
        <button onClick={this.add}>点我+1</button>
      </div>
    )
  }
}
